This invention relates to processes for reacting amines with isatoic anhydrides and, more specifically, to processes for reacting aminated poly(alkylene glycols) with isatoic anhydrides to make o-aminophenyl derivatives of such poly(alkylene glycols).
Processes for reacting aminated poly(alkylene glycols) with isatoic anhydrides to make o-aminophenyl derivatives of such poly(alkylene glycols) are known and are described, for example, in U.S. Pat. Nos. 4,180,644: 4,191,706: 4,609,683: and 4,609,684. Such derivatives are useful in the preparation of urethane and/or urea polymers as additives to modify the physical properties of the urethane, such as tensile strength, elongation, tear strength, flexibility, and hardness. Such additives are also useful to control the reactivity of the reaction mixture. Since urethane and/or urea polymers are typically prepared by reacting active hydrogen-containing compounds with polyisocyanates, introducing active hydrogen-containing compounds into the reaction mixture which have varying degrees of reactivity advantageously allows one to control the speed of the reaction of the components.
In the processes described in the above-mentioned patents, the process comprises reacting aminated poly(alkylene glycols) with isatoic anhydrides. However, the reaction product of such processes does not react completely with polyisocyanates to form urethanes and/or ureas. Such prior art processes may lead to the formation of a substantial amount of a side product comprising a corresponding urea carboxylate, which does not react with polyisocyanates. Other processes use large stoichiometric amounts of polyamine to achieve a higher conversion rate and higher yield. These processes result in a large amount of excess polyamine in the reaction mixture, which must be separated from the desired product. A process for the preparation of o-aminophenyl derivatives of aminated poly(alkylene glycols) which does not produce substantial amounts of urea carboxylate, nor require large amounts of polyamine to be separated from the reaction product, is desired.